TreeView update

namespace TestTreeViewThread
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Holds the root node of the TreeView added last
        /// </summary>
       // TreeNode tn;

        /// <summary>
        /// Fills up the TreeView.
        /// </summary>
        //public void FillTree()
        //{
        //    // Create 10 root nodes
        //    for (int i = 0; i < 10; i++)
        //    {
        //        //Create the node, here we must call on the form's thread otherwise we get an exception:
        //        //Action being performed on this control is being called from the wrong thread. Marshal
        //        //to the correct thread using Control.Invoke or Control.BeginInvoke to perform this action.
        //        treeView1.Invoke(new Add(Add1), new object[] { i });
        //        //Create 10 subnodes for each root node
        //        for (int j = 0; j < 10; j++)
        //        {
        //            //Create the node, here we must call on the form's thread otherwise we get an exception:
        //            //Action being performed on this control is being called from the wrong thread. Marshal
        //            //to the correct thread using Control.Invoke or Control.BeginInvoke to perform this action.
        //            treeView1.Invoke(new Add(Add2), new object[] { i * 10 + j });
        //            //Slow down the filling process
        //            //System.Threading.Thread.Sleep(1000);
        //        }
        //        //toolStripProgressBar1.PerformStep();
        //    }
        //    //treeView1.Update();
        //}

        public void ListDirectory(DirectoryInfo path)
        {
            treeView1.Nodes.Add(CreateDirectoryNode(path));
        }


        public void Addnode(DirectoryInfo dirinfo)
        {
            Invoke(new AddCDAnode(ListDirectory), new object[] { dirinfo });
        }


        private TreeNode CreateDirectoryNode(DirectoryInfo directoryInfo)
        {
            var directoryNode = new TreeNode(directoryInfo.Name);
            foreach (var directory in directoryInfo.GetDirectories())
            {
                //Statustext = directory.FullName;
                directoryNode.Nodes.Add(CreateDirectoryNode(directory));
            }
            foreach (var file in directoryInfo.GetFiles())
                directoryNode.Nodes.Add(new TreeNode(file.Name));
            return directoryNode;
        }


        public delegate void AddCDAnode(DirectoryInfo dirinfo);

        //public delegate void Add(int i);

        /// <summary>
        /// Adds a root node.
        /// </summary>
        /// <param name="i">Label of the new node.</param>
        //public void Add1(int i)
        //{
        //    tn = treeView1.Nodes.Add(i.ToString());
        //}

        ///// <summary>
        ///// Adds a node under the current node.
        ///// </summary>
        ///// <param name="i">Label of the new node.</param>
        //public void Add2(int i)
        //{
        //    tn.Nodes.Add(i.ToString());
        //    treeView1.ExpandAll();
        //}

        /// <summary>
        /// The filling thread's starting point
        /// </summary>
        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            DirectoryInfo dir = new DirectoryInfo(@"\\server\trabajos 2013\");
            Addnode(dir);
        }

        /// <summary>
        /// When form is loading
        /// </summary>
        private void Form1_Load(object sender, EventArgs e)
        {
            //Start filling the TreeView on a separate thread
            backgroundWorker1.RunWorkerAsync();
        }
    }
}